Is there a security issue with Instagram android app?

I've looked on the Instagram site for this issue and how to report a security issue, but cannot find anything. This evening, I downloaded the Instagram android app and logged in using my Facebook ID. It asked if I wanted to follow my friends, I said no and proceeded. At the main screen it reported I had photos, followers and that I followed people. I thought this was odd, as I have never used Instagram. Still, I considered I used it in the past when I had an iPhone and forgot. As I went through the information it became apparent that this was not my account. I had complete access to the photos and settings for another user's instagram account. I believe I know what caused the issue and understand that it can be replicated. What is the proper way to report this to Instagram so they can fix the problem? I have screenshots of the main screen and settings screen for proof.